Remove or waive unused variables (-Werror)

riscv/debug_module.cc

@@ -450,7 +450,6 @@ bool debug_module_t::dmi_read(unsigned address, uint32_t *value)
               } else {
                 dmstatus.allresumeack = false;
               }
-              auto hart = sim->get_harts().at(hart_id);
               if (!hart_available(hart_id)) {
                 dmstatus.allrunning = false;
                 dmstatus.allhalted = false;

riscv/dts.cc

@@ -424,7 +424,6 @@ int fdt_parse_isa(const void *fdt, int cpu_offset, const char **isa)
 int fdt_parse_hartid(const void *fdt, int cpu_offset, uint32_t *hartid)
 {
   int len, rc;
-  const void *prop;
   const fdt32_t *val;
 
   if ((rc = check_cpu_node(fdt, cpu_offset)) < 0)

riscv/sim.cc

@@ -137,7 +137,6 @@ sim_t::sim_t(const cfg_t *cfg, bool halted,
     dtb = strstream.str();
     dts = dtb_to_dts(dtb);
   } else {
-    std::pair<reg_t, reg_t> initrd_bounds = cfg->initrd_bounds;
     std::string device_nodes;
     for (const device_factory_sargs_t& factory_sargs: device_factories) {
       const device_factory_t* factory = factory_sargs.first;

riscv/v_ext_macros.h

@@ -454,7 +454,7 @@ static inline bool is_overlapped_widen(const int astart, int asize,
 
 #define VFP_VF_CMP_PARAMS(width) \
   float##width##_t rs1 = f##width(READ_FREG(rs1_num)); \
-  float##width##_t vs2 = P.VU.elt<float##width##_t>(rs2_num, i);
+  float##width##_t UNUSED vs2 = P.VU.elt<float##width##_t>(rs2_num, i);
 
 #define VFP_VF_PARAMS(width) \
   float##width##_t &vd = P.VU.elt<float##width##_t>(rd_num, i, true); \